The Role of Monoamine Oxidase and Atherogenic Index in Newly Diagnosed and Tamoxifen Treated Women with Breast Cancer Disease

Breast cancer (BC) is the most epidemic malignancy of women worldwide that leads to cause of morbidity and mortality. Tamoxifen (TAM) is the common therapy used in the BC treatment. Monoamine oxidases are enzymes linked to the progression of many types of carcinomas through its consideration on the production of reactive oxygen species. This study aimed to clarify the correlations between MAO isoforms (MAOs), atherogenic index, TAM, and their roles in the BC progression. 60 newly diagnosed and 60 TAM treated women with BC, as well as 50 healthy volunteers were included in this study. Parameters including MAOs activities, lipid profile, malondialdehyde, and total protein were determined before and after treatment with TAM. The activities of total MAO, MAO-A, MAO-B, and semi-carbazide-sensitive amine oxidase (SSAO) were significantly (P< 0.0001) decreased in newly diagnosed and TAM-treated women compared with healthy individual. However, the activities of all tested enzymes were elevated significantly (P< 0.0001) in TAM-treated women compared with the newly diagnosed women. The strong positive correlations were found among MAOs in response to TAM treatment. Receiver operating characteristic showed a higher sensitivity and specificity for MAOs in discrimination between newly diagnosed and TAM-treated women. Atherogenic index was significantly increased (P< 0.0001) in newly diagnosed and in TAM-treated women compared with control. The findings of this study indicated that BC patients are more vulnerable to cardiovascular diseases, independent of TAM and MAOs effect. Based on the forgoing, MAOs can be used as a diagnostic marker for BC progression.